Fig. 6

Effect of proteasome inhibitors on FAD-linked PS1-expressing HEK293 cells. Stably transfected HEK293 cells expressing mutated PS1 or ΔE9-PS1 were incubated with 5 µM of lactacystin or with 25 µM of Z-IE(Ot-Bu)A-Leucinal during the indicated time periods, then cells were lysed and immunoreactivities of HMW-PS1 and LMW-PS1 (indicated by upper and lower arrows, respectively) were revealed with αPS1Loop antibody (A) as described in Materials and Methods. Histograms in B represent the densitometric analysis of HMW-PS1 (black bars) and LMW-PS1 (white bars) immunoreactivity and are the means ± S.E.M of four independent experiments.